'std::logic_error' what(): basic_string::_S_construct NULL not valid ERROR Help Me!

Hi,

I have a very very big problem.
After 1-2 hours or 5 minutes, my channel is closed
And I have this message on putty screen :

terminate called after throwing an instance of 'std::logic_error'
what(): basic_string::_S_construct NULL not valid

Please help me